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Biomedical subjects

M Harper

Publications and source records attributed to M Harper.

At least 55 records · Page 3Linked to original sources
PubMed1995

Phosphorylation by p34cdc2 regulates spindle association of human Eg5, a kinesin-related motor essential for bipolar spindle formation in vivo.

We have isolated a human homolog of Xenopus Eg5, a kinesin-related motor protein implicated in the assembly and dynamics of the mitotic spindle. We report that microinjection of antibodies against human Eg5 (HsEg5) blocks centrosome migration and causes HeLa cells to arrest in mitosis with monoastral microtubule arrays. Furthermore, an evolutionarily conserved cdc2 phosphorylation site (Thr-927) in HsEg5 is phosphorylated specifically during mitosis in HeLa cells and by p34cdc2/cyclin B in vitro. Mutation of Thr-927 to nonphosphorylatable residues prevents HsEg5 from binding to centrosomes, indicating that phosphorylation controls the association of this motor with the spindle apparatus. These results indicate that HsEg5 is required for establishing a bipolar spindle and that p34cdc2 protein kinase directly regulates its localization.

Amino Acid Sequence↗
PubMed1995

Osteomyelitis and septic arthritis in children: appropriate use of imaging to guide treatment.

Modern imaging techniques have become essential components of the management of acute osteomyelitis and septic arthritis in children. This article addresses the role of these techniques, based on clinical practice guidelines recently developed at a children's hospital by an interdisciplinary group. The recommendations reflect a review of the literature and an analysis of our own experience with 84 children treated for musculoskeletal sepsis during the past 3 years. We attempt to optimize imaging resources by analyzing the unique aspects of these infections in the pediatric skeleton, the clinical needs at different stages of the disease, and the relative strengths and weaknesses of the various imaging procedures. Our goal was to define the use of imaging in cases of osteomyelitis and septic arthritis in children in specific clinical scenarios in which additional information is likely to lead to management modification.

Acute Disease↗
PubMed1994

Community-based asthma care: trial of a "credit card" asthma self-management plan.

Although asthma self-management plans are widely recommended as essential in the long-term treatment of adult asthma, there have been few studies examining their use. Our objective was to assess the effect of a "credit card" adult asthma self-management plan in a community experiencing major health problems from asthma, by means of a before and after intervention trial of the efficacy of the "credit card" plan, when introduced through community-based asthma clinics. The participants were 69 Maori people with asthma. The "credit card" plan consisted of written guidelines for the self-management of asthma, based on self-assessment of asthma severity, printed on a plastic card. On one side, management guidelines were based on the interpretation of peak expiratory flow rate (PEFR) recordings, whilst the reverse side was based on symptoms. The outcome measures used were before and after comparison of markers of asthma morbidity and requirement for acute medical treatment; and a structured questionnaire assessing the acceptability and use of the credit card plan. Following the introduction of the plan, the mean PEFR increased from 347 to 389 l.min-1, the percentage of nights woken fell from 30.4 to 16.9%, and the number of days "out of action" fell from 3.8 to 1.7%. The requirements for acute medical treatment also fell during the intervention period. Most participants commented favourably on the content and usefulness of the plan. In the situation of worsening asthma, 28% of subjects found the peak flow side of the card most helpful, 7% the symptoms side, and 48% found both sides equally helpful.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1994

State of the art in geropsychiatric nursing.

1. Almost 1 million people in the United States were 65 years or older in 1989. This group is anticipated to more than double, increasing to over 68 million by the year 2050. 2. Evidence from a range of studies suggests that older persons are at risk for ongoing disability as a result of the underuse of mental health services. 3. Continuing advances in our understanding of mental disorders of the elderly--particularly with respect to management and treatment--point to the necessity of ongoing continuing education for nurses practicing in all sites that serve older persons.

Age Factors↗
PubMed1993

Trial of an asthma action plan in the Maori community of the Wairarapa.

AIMS: An asthma action plan has been tested in a study conducted by Wairarapa Maori community health workers and the Wellington asthma research group. There were several distinctive features of the project, including the programme of marae-based asthma clinics, and the partnership between the researchers and the Maori community groups. This paper describes the process by which the study was conducted since this experience may be relevant to future Maori health research projects. METHODS: The programme was launched with a series of hui at marae in the Wairarapa, and marae-based clinics were set up. These were followed up by further support from the Maori community health workers who helped people to keep diaries to monitor their asthma, and generally maintained contact. The severity of asthma in the participants was compared for a two-month period before the action plan was introduced, and for a four-month period after the plan was introduced. RESULTS: There was a high participation rate, with 91% (63/69) of participants finishing the programme, 75% of whom adequately completed their daily asthma diaries. Asthma control improved significantly in the participants. They commented positively on the programme, and particularly on the marae-based clinics. CONCLUSIONS: The study was successful in terms of participation in the marae-based clinics, acceptance and use of the plan, and improvement in asthma control of the participants. The findings indicate what can be achieved when researchers and Maori community groups work in partnership.

Asthma↗
PubMed1992

Antibodies to protein P in systemic lupus erythematosus.

A synthetic peptide was used to develop an enzyme linked immunosorbent assay (ELISA) to detect antibodies to the ribosomal proteins P0, P1, and P2. Significantly increased levels of IgG antibodies to protein P were found in 16% (18/116) of patients with systemic lupus erythematosus but slightly increased levels were detected in 2% (2/98) of patients with rheumatoid arthritis and one normal control subject. No association was observed between the presence of IgG antibodies to protein P and either lupus psychosis or depression. Sequential studies in individual patients failed to show an association between antibody levels and the development of psychosis.

Antibodies↗
PubMed1991

Rabbit blastocysts accumulate [3H]quinuclidinyl benzilate in vitro.

Day-6 rabbit blastocysts were able to accumulate [3H]quinuclidinyl benzilate (QNB) from their environment. This accumulation was reduced approximately 50% in the presence of 1.5 x 10(-4) M atropine (an accepted antagonist for ligands which bind to muscarinic cholinergic receptors). The accumulation of QNB was sensitive to temperature and was apparently saturable. In the presence of 2 nM QNB, Day-6 blastocysts accumulated 30.3 +/- 2.0 fmoles per blastocyst. When the cellular elements alone were examined, lesser amounts of specific binding were detected. Owing to the complexity of this multicompartmental system, Scatchard analysis did not provide meaningful results. This accumulation appears higher than that reported for other tissues such as rabbit heart homogenates or rabbit uterine endometrial cells. This muscarinic cholinergic accumulation may have some roll in blastocyst-maternal recognition.

Animals↗
PubMed1991

Steroids and the prostate.

Interelationships between steroid and growth factor regulation of cell proliferation has been examined in two androgen sensitive prostatic cell lines, grown in defined medium. The cell lines used were derived from normal (CAPE) and neoplastic (LNCaP) tissues. The growth of both cell lines was elevated by challenge with serum, androgens and epidermal growth factor (EGF) used as single agents. The effects of androgen in CAPE were small, but significant while the profound effects of these agents on the growth of LNCaP were confirmatory of other studies. Androgens upregulated EGF receptor expression in LNCaP measured by both ligand binding capacity and mRNA analysis. This was not observed in the CAPE cells. Addition of serum (whole or charcoal stripped) suppressed the observed androgenic stimulation of EGF receptor expression in LNCaP. This apparent anomaly is discussed in relation to the growth enhancing properties of serum in these cell lines and in the wider context of normal and neoplastic growth control in the prostate.

Androgens↗
PubMed1990

Tissue aluminum concentrations stability over time, relationship to age, and dietary intake.

Aluminum concentration was measured in serum, whole blood, hair, and urine by neutron activation analysis. Seventy-six nondemented subjects were investigated. Not all assays were done on all subjects (e.g., serum aluminum on 76 subjects, whole blood aluminum on 42 subjects), but tissue aluminum concentrations were estimated on more than one occasion on 32 subjects. The mean +/- SD aluminum concentration in serum was 0.219 +/- 0.063 micrograms/ml (N = 76), in whole blood 0.368 +/- 0.091 micrograms/ml (N = 42), in urine 0.092 +/- 0.076 micrograms/ml (N = 42), and in hair 6.42 +/- 2.22 micrograms/g (N = 42). Using product moment correlation coefficient there was no significant correlation between age and tissue aluminum concentrations, nor between dietary intake of aluminum and tissue aluminum. The tissue aluminum concentrations were not stable over time even when dietary intake was constant. Tissue aluminum concentrations were measured in 14 patients after 7 days of dietary control and repeated approximately 6 weeks later, again after 7 days of dietary control. There was no significant correlation between the two estimations in any tissue measured. These results suggest that raised tissue aluminum concentrations reported in Alzheimer's disease are not an exaggeration of a normal ageing process, are not likely to be simply secondary to increased dietary aluminum intake, and that Alzheimer's disease does not represent the chronic toxic effect of moderately raised aluminum levels at the upper end of the normal distribution.

Adult↗
PubMed1990

Rapid and quantitative detection of enzymatically amplified HIV-1 DNA using chemiluminescent oligonucleotide probes.

A hybridization protection assay (HPA) that uses acridinium ester (AE) labeled oligonucleotide probes which are specific for a conserved gag gene region of human immunodeficiency virus type 1 (HIV-1) was developed to measure the amount of HIV-1 nucleic acid. Hybridization of the single-stranded probes with their target HIV-1 sequences protected the chemiluminescent AE group from subsequent alkaline hydrolysis. The chemiluminescence from the residual AE could be easily quantitated in a luminometer. The entire process comprising template dissociation, hybridization, alkaline hydrolysis, and chemiluminescence measurement can be completed in less than one hour and does not require the separation of hybridized probe from unhybridized probe. We demonstrated that HPA could quantitatively measure the amount of DNA amplified by polymerase chain reaction. A comparative study using amplified DNA from the peripheral blood mononuclear cells (PBMC) of HIV seropositive and seronegative persons showed that HPA was as sensitive as the previous methods using 32P-labeled DNA probes.

Acridines↗
PubMed1990

Management of health risks in the arsenic production industry: modern production in Chile in the context of past experience in Britain.

The hazards presented by arsenic are well known, and the notoriety gained by its use as a poison in previous years has affected attitudes towards the commercial production and employment of a very useful substance. It is not widely realized that Britain was the world's largest producer of arsenic around the turn of the century. Production has now ceased and any reserves that still exist will probably remain unexploited, despite the modern requirement for arsenic by the wood treatment and microelectronics industries. This demand is being satisfied by mines in other countries which use essentially the same refining process as that employed in England a century ago. This paper compares what is known about conditions of work and health in the English arsenic industry then with modern conditions at a Chilean production plant, and shows how the perception and management of the risks involved in a hazardous operation stems from the complex inter-relationship of technological, social, political and economic factors. In particular, the results of this survey explain why, in many previous surveys, a poor correlation was found between airborne and urinary arsenic measurements. Both measures appear to be strongly influenced by the particular type of work undertaken and this can be related to the chemical form of the arsenic present. Within each job category, the most important factor affecting their correlation is the difference in use of respiratory protection equipment.

Arsenic↗
PubMed1988

Occupational health aspects of the arsenic extractive industry in Britain (1868-1925).

A historical survey into the occupational hazards of mining and refining arsenic is presented together with the measures adopted for their control. The industry is placed in the social perspective of its time and it is suggested that this experience could be of value to those who may encounter similar problems where arsenic is extracted elsewhere in the world.

Arsenic Poisoning↗
PubMed1988

Lymphadenopathy in HIV (HTLV-III/LAV) infected subjects: the role of virus and follicular dendritic cells.

Studies of human immunodeficiency virus (HIV) associated lymphadenopathy by histopathology and immunopathology showed conspicuous changes of follicular B-cell areas from a marked hyperplasia to complete involution. Immunohistochemistry showed a corresponding increase in follicular dendritic reticulum cells (FDRC) followed by progressive destruction of these cells during involution, concomitant with invasion of follicles by T-cells. HIV gag antigens were predominantly associated with FDRC in hyperplastic follicles and diminished during involution. Virus replication was by in situ hybridization seen predominantly in follicles, presumably reflecting productive infection of CD4+ cells and/or FDRC. It is concluded that local effects of the virus play an important role in HIV lymphadenopathy. The marked cytopathogenic effects on FDRC indicate that HIV infection with lymphadenopathy represents not only a disease of CD4+ cells but also of follicular antigen presenting cells (FDRC).

AIDS-Related Complex↗
PubMed1987

Antigen specificity and cross-reactivity of monoclonal anti-lysozyme antibodies.

Twenty-seven murine monoclonal anti-hen egg-white lysozyme (HEL) antibodies were tested with a panel of nine antigens; eight avian lysozymes and human lysozyme. The antibodies were arranged into 10 groups based on their antigen specificity and cross-reactivity. Antigenic determinants recognized by each group of antibodies were tentatively identified. They are located at different points of the HEL accessible surface in agreement with the notion that its entire surface has an antigenic potential. The affinity constants of antibodies representative of seven of the 10 groups range from 0.79 X 10(7) to 5.3 X 10(7) M-1. Heteroclitic antibodies occurring in some of the groups bind heterologous lysozymes with somewhat higher association constants than those for the homologous antigen (HEL). Their broader specificities do not correlate with overall lower association constants, but rather with the occurrence of public epitopes in the panel of avian lysozymes. Although the reaction of two antibodies with the solid-phase coupled antigen is not always additive, detailed interpretation of these results and the observation of actual ternary complexes Fab-HEL-Fab rules out the occurrence of conformational changes in the complexed antigen.

Amino Acid Sequence↗
PubMed1987

Multilesion coronary angioplasty: clinical and angiographic follow-up.

Determination of the restenosis rate after multilesion percutaneous transluminal coronary angioplasty is an important consideration in defining expanded indications for the procedure. Of 209 patients who underwent successful multilesion coronary angioplasty, 55 symptomatic and 74 asymptomatic patients were restudied an average of 7 +/- 4 months after dilation. The restenosis rate was 82% (45 of 55) in the symptomatic patients and 30% (22 of 74) in the asymptomatic patients (p less than 0.001). Only 4% of the asymptomatic patients had restenosis at more than one dilation site. When only patients who developed a restenosis were considered, the restenosis occurred at more than one dilation site in 47% (21 of 45) of the symptomatic group versus 14% (3 of 22) of the asymptomatic group (p less than 0.05). When all recurrent stenoses were examined, the severity of the luminal narrowing was greater than or equal to 70% in 64% (45 of 70) of the stenotic lesions in the symptomatic patients versus 31% (8 of 26) of the stenotic lesions in the asymptomatic patients (p less than 0.05). Proximal left anterior descending coronary artery disease, increased length of the stenotic narrowing, male gender and diabetes were associated with an increased incidence of restenosis by multivariate analysis. Patient-related variables were not predictive of multilesion restenosis. In conclusion, the majority of patients are clinically improved after multilesion coronary angioplasty. Recurrent symptoms after multilesion coronary angioplasty are frequently associated with multilesion restenosis and a more severe degree of restenotic narrowing. Restenosis at more than one dilation site is uncommon in the asymptomatic patient.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗